Waitress is meant to be a production-quality pure-Python WSGI server with
very acceptable performance. It has no dependencies except ones which live
in the Python standard library. It runs on CPython on Unix and Windows under
Python 2.6+ and Python 3.3+. It is also known to run on PyPy 1.6.0+ on UNIX.
It supports HTTP/1.0 and HTTP/1.1.
Python 3 version.